python自动裁剪图像代码分享

yipeiwu_com6年前Python基础

本代码可以帮你自动剪切掉图片的边缘空白区域,如果你的图片有大片空白区域(只要是同一颜色形成一定的面积就认为是空白区域),下面的python代码可以帮你自动切除,如果是透明图像,会自动剪切大片的透明部分。

本代码需要PIL模块

pil相关介绍

PIL:Python Imaging Library,已经是Python平台事实上的图像处理标准库了。PIL功能非常强大,但API却非常简单易用。

由于PIL仅支持到Python 2.7,加上年久失修,于是一群志愿者在PIL的基础上创建了兼容的版本,名字叫Pillow,支持最新Python 3.x,又加入了许多新特性,因此,我们可以直接安装使用Pillow。

import Image, ImageChops
 
def autoCrop(image,backgroundColor=None):
  '''Intelligent automatic image cropping.
    This functions removes the usless "white" space around an image.
    
    If the image has an alpha (tranparency) channel, it will be used
    to choose what to crop.
    
    Otherwise, this function will try to find the most popular color
    on the edges of the image and consider this color "whitespace".
    (You can override this color with the backgroundColor parameter) 
 
    Input:
      image (a PIL Image object): The image to crop.
      backgroundColor (3 integers tuple): eg. (0,0,255)
         The color to consider "background to crop".
         If the image is transparent, this parameters will be ignored.
         If the image is not transparent and this parameter is not
         provided, it will be automatically calculated.
 
    Output:
      a PIL Image object : The cropped image.
  '''
   
  def mostPopularEdgeColor(image):
    ''' Compute who's the most popular color on the edges of an image.
      (left,right,top,bottom)
       
      Input:
        image: a PIL Image object
       
      Ouput:
        The most popular color (A tuple of integers (R,G,B))
    '''
    im = image
    if im.mode != 'RGB':
      im = image.convert("RGB")
     
    # Get pixels from the edges of the image:
    width,height = im.size
    left  = im.crop((0,1,1,height-1))
    right = im.crop((width-1,1,width,height-1))
    top  = im.crop((0,0,width,1))
    bottom = im.crop((0,height-1,width,height))
    pixels = left.tostring() + right.tostring() + top.tostring() + bottom.tostring()
 
    # Compute who's the most popular RGB triplet
    counts = {}
    for i in range(0,len(pixels),3):
      RGB = pixels[i]+pixels[i+1]+pixels[i+2]
      if RGB in counts:
        counts[RGB] += 1
      else:
        counts[RGB] = 1  
     
    # Get the colour which is the most popular:    
    mostPopularColor = sorted([(count,rgba) for (rgba,count) in counts.items()],reverse=True)[0][1]
    return ord(mostPopularColor[0]),ord(mostPopularColor[1]),ord(mostPopularColor[2])
   
  bbox = None
   
  # If the image has an alpha (tranparency) layer, we use it to crop the image.
  # Otherwise, we look at the pixels around the image (top, left, bottom and right)
  # and use the most used color as the color to crop.
   
  # --- For transparent images -----------------------------------------------
  if 'A' in image.getbands(): # If the image has a transparency layer, use it.
    # This works for all modes which have transparency layer
    bbox = image.split()[list(image.getbands()).index('A')].getbbox()
  # --- For non-transparent images -------------------------------------------
  elif image.mode=='RGB':
    if not backgroundColor:
      backgroundColor = mostPopularEdgeColor(image)
    # Crop a non-transparent image.
    # .getbbox() always crops the black color.
    # So we need to substract the "background" color from our image.
    bg = Image.new("RGB", image.size, backgroundColor)
    diff = ImageChops.difference(image, bg) # Substract background color from image
    bbox = diff.getbbox() # Try to find the real bounding box of the image.
  else:
    raise NotImplementedError, "Sorry, this function is not implemented yet for images in mode '%s'." % image.mode
     
  if bbox:
    image = image.crop(bbox)
     
  return image
 
 
 
#范例:裁剪透明图片:
im = Image.open('myTransparentImage.png')
cropped = autoCrop(im)
cropped.show()
 
#范例:裁剪非透明图片
im = Image.open('myImage.png')
cropped = autoCrop(im)
cropped.show()

 总结

以上就是本文关于python自动裁剪图像代码分享的全部内容,希望对大家有所帮助。如有不足之处,欢迎留言指出。感兴趣的朋友可以继续参阅本站:

python图像常规操作

python好玩的项目—色情图片识别代码分享

Python生成数字图片代码分享

相关文章

分享vim python缩进等一些配置

VIM python下的一些关于缩进的设置: 第一步: 打开终端,在终端上输入vim ~/.vimrc,回车。 第二步: 添加下面的文段: set filetype=p...

Python中运算符"=="和"is"的详解

前言 在讲is和==这两种运算符区别之前,首先要知道Python中对象包含的三个基本要素,分别是:id(身份标识)、python type()(数据类型)和value(值)。is和==都...

浅谈Python中用datetime包进行对时间的一些操作

1. 计算给出两个时间之间的时间差 import datetime as dt # current time cur_time = dt.datetime.today() # one...

Python常用库推荐

IPython + ptpython,完美体验 首先是安装 pip install ipython ptpython 然后使用 ptipython 有什么好处 1. IPython...

小米5s微信跳一跳小程序python源码

本文实例为大家分享了微信跳一跳小程序python源码,供大家参考,具体内容如下 微信跳一跳小程序小米5s源码python,搭建环境后亲测可用。 # coding: utf-8 imp...